基于DNA修饰电极的环境电化学研究

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1、摘要本文首先采用恒电位吸附法将DNA成功固定于预处理过的玻碳电极表面由2+2+于Ru(bpy)2dppz与DNA的结合力非常强选用嵌入剂Ru(bpy)2dppz作为电化学信号指示剂制得Ru-dppz/DNA/GCE(ox)电极研究了甲醛在Ru-dppz/DNA/2+GCE(ox)上的电化学行为结果表明甲醛能降低Ru(bpy)2dppz在+1.01V的氧化峰2+电流并且甲醛浓度在1~20mmol/L范围内与Ru(bpy)2dppz氧化峰呈良好的线性关系相关系数为0.9961检测限为1mmol/L利用液相沉积法通过掺杂DNA和MB制得DNA/MB/TiO2/GCE电极发现共掺杂DNA和MB可显

2、著提高MB的电极上的氧化还原电流研究了不同pH值和扫速对DNA/MB/TiO2/GCE电化学行为的影响结果表明DNA/MB/TiO2/GCE在0.1mol/LpH5.0醋酸醋酸钠缓冲溶液中对H2O2有着很好的催化性能MB还原峰电流与双氧水浓度在1~50mmol/L范围内呈良好的线性关系相关系数为0.9884检测限为1mmol/L采用环境扫描电镜ESEM紫外-可见吸收光谱UV-Vis和交流阻抗EIS技术对液相沉积法制得的DNA/TiO2/GCE电极进行了表征通过光电催化性能实验发现沉积液DNA浓度为1mg/mL时在紫外光254nm照射下DNA/TiO2/GCE的光电流是TiO2/GCE的3倍

3、且在紫外光连续照射3h中DNA/TiO2/GCE的光电流不断增大以MB为目标降解物对DNA/TiO2/GCE和TiO2/GCE的光电催化性能进行了比较发现在外加偏压的作用下DNA/TiO2/GCE具有较好光电催化降解性能关键词DNA嵌入剂液相沉积法光电催化IAbstractPaperhereimmobilizedDNAontothepretreatedglassycarbonelectrodewith2+appliedpositivepotential,andRu(bpy)2dppzwasselectedaselectrochemicalindicatorforithashigh-affi

4、nitycombinationwithDNAresultingRu-dppz/DNA/GCE(ox)wasmade.TheelectrochemicalbehaviorofformaldehydeonRu-dppz/DNA/GCE(ox)wasstudied,anditwasfoundthatformaldehydecouldreducetheoxidationpeakcurrentof2+Ru(bpy)2dppzat+1.01V.Theoptimumexperimentalconditionsforthedetectionofformaldehydewereexplored,andthe

5、calibrationwaslinearforformaldehydeintherangeof1~20mmol/L,withacorrelationcoefficientof0.9961.Thelimitofdetectionwas1mmol/L.DNA/Methyleneblue(MB)/TiO2/GCEwerepreparedbytheliquidphasedeposition(LPD)process.ItwasfoundthattheoxidationandreductionpeakcurrentsofMBwereenhancedonelectrodesgreatlywithcodo

6、pingMBandDNA.TheresultsindicatedDNA/MB/TiO2/GCEhadgoodelectrochemicalactivitytoH2O2in0.1mol/LpH5.0HAc-NaAcbuffersolution.ThereductionpeakcurrentswerelinearwithH2O2concentrationintherangeofcalibrationwaslinearforH2O2intherangeof1to20mmol/L,withacorrelationcoefficientof0.9884andthelimitofdetectionwa

7、s1mmol/L.TheDNA/TiO2/GCEelectrodewaspreparedinthisarticlebyliquidphasedeposition(LPD)withdopingDNA.TheDNA/TiO2/GCEwascharacterizedbyESEMandUV-visspectraandEIS.Thephotoelectrochemicalmeasurementsindicatedthattheph